Tag Archives: FLSMIDTH (PTY) LTD

FLSMIDTH OFFERS MODULAR RC® PLANTS ON LOW-RISK TERMS

As the fines recovery gains achieved by REFLUX™ Classification (RC™) technology are extended to a wider range of commodities, FLSmidth is making mines an offer they can’t refuse: to share the value of expanded production – including retreatment of waste dumps – at no cost to themselves.

The profit-share option is one of a range of contractual and financial alternatives that the leading engineering Original Equipment Manufacturer (OEM) is putting on the table as part of its commitment to sustainable productivity for its customers, according to FLSmidth’s capital sales director for sub-Saharan Africa, Roy Hazell.

“We are putting our money where our mouth is– this is how confident we are in this technology,” says Hazell. “We can even operate the plant on the customer’s behalf; no‑one knows our equipment better than we do and we can ensure that it performs to expectation.”

Other options for customers include a toll treatment arrangement, while some customers may prefer to purchase the solution outright and operate it themselves as a standalone unit to augment production levels.

He says the modular RC solution is ideal for any mining company that has dumps or stockpiles of fines where they would like to recover minerals, but where the quantities do not justify the building of a dedicated fixed plant. The modular format allows a short term treatment plant of capacities around 100 tph to be set up without disrupting any existing process facilities. At the same time, the modular format can even be expanded for customers who want production capacity up to 400 to 600 tph although these plants are more likely to a fixed solution.

The sector is recognising that the RC concept offers better recovery rates than spirals when dealing with fine particles, more effectively separating materials of different densities. With one modular RC plant already commissioned and in ramp-up and optimisation phase at a platinum mine near Rustenburg, FLSmidth is developing these plants for coal fines and will take the modular concept to other commodities such as gold.

PGM producers have gained particular value from RC technology in terms of recovering chromite – a contaminant in PGM concentrate – as an added source of revenue.

BOLTED THICKENERS ARE THE FUTURE – FLSMIDTH

The concept of bolted thickeners is growing in popularity. According to FLSmidth senior account manager Ricus van Reenen, this is a fit-for-purpose, high quality dewatering solution with reduced project construction risk and duration.

These benefits resulted in FLSmidth securing an order in July 2017 for a 24 metre diameter high-rate thickener from a South African iron ore mining company.

“Although this concept has been around for at least a decade, it is becoming more commonly used,” says van Reenen. “With a bolted tank, the whole thickener is constructed inside a purpose-designed fabrication facility with all welding, sandblasting and painting taking place under controlled conditions. This guarantees that everything fits as it should so there are no unexpected delays on site.”

Thickeners have traditionally been constructed on site; all rolled and bent plates are transported to the required location where they are welded onto the prefabricated support structure and radial beams.

“This process can take weeks to complete, as there are kilometres of welding runs required,” he says. “Moreover, the considerable weight of the material in the finished tank – several thousand tonnes – means that the weld quality needs to be high and coded welders must conduct the work.”

These welders often have to be accommodated on site for extended periods of time, which adds to the cost; cross-border work often involves the added burden of obtaining work permits and special visas for these workers.

Sandblasting of the welding runs is then necessary, as well as a final coat of paint. In addition to the extra costs, the work is highly weather dependent and delays can be caused by rain or excessive dust.

“Weather related delays can cause time over-runs for the contractor, which can then lead to penalty costs,” he says. “This sort of project risk is one of the main reasons why contractors are choosing bolted thickeners. As a contractor, your time on site is where your most significant risk will lie.”

After the construction of a bolted thickener in a workshop, the whole tank can be transported to site where the bulk of the on-site work can be undertaken by a mechanical supervisor, who oversees the lifting and placement with the support of a rigger and a crane driver. Local labour can be used to fit the necessary bolts into the structure, and a technical specialist can come in to torque the bolts.

“Once in place, only touch-up painting is required, so poor weather won’t be a serious risk factor,” says van Reenen. “Ensuring that deadlines are met means on-time commissioning, which aligns well with FLSmidth’s role as productivity partner to mining projects.”

He notes that FLSmidth has supplied at least 20 projects globally with bolted thickener tanks, putting close to 40 of these units into the market in recent years. The largest unit was a 45 metre diameter high-rate thickener, while the more specialised deep cone thickeners have also been built in this way up to a size of 35 metres in diameter.

ROCK INTRUSIONS A PROBLEM WHEN SPECIFYING SIZERS AND BREAKERS

With coal miners moving into more difficult geological conditions, a detailed characterisation of the ore body is increasingly vital when specifying feeder breakers or mineral sizers, according to PC Kruger, capital sales manager at FLSmith Buffalo.

“Most of the ‘easy’ coal seams in the Witbank coalfields have been mined,” says Kruger, “and what remains tends to include a high level of hard rock intrusion as well as tramp material such as steel, wood and concrete.”

In particular, a strip mining of old underground bord-and-pillar mine often encounters a substantial portion of rock, which has a much higher ultimate compressive strength (UCS) than the coal. While the UCS of coal ranges from about 40 MPa to about 60 MPa tests in the Witbank region, over a number of decades, have found that some rock intrusions easily measure up to 210 MPa in strength.

He says that feeder breakers are well suited for most underground mining conditions where the coal is relatively soft and homogenous.

“However, they are not designed to deal with high strength material,” he says. “Where there are regular hard rock intrusions, you will generally opt for mineral sizers.”

Another critical consideration in specifying equipment for coal processing is the principle of reduction ratios in each stage of sizing. Kruger says the ‘the rules of the game’ require that, in the primary sizing stage, the ratio between the input size of coal and the output size should be about 4:1 or 5:1.

“In other words, a large chunk of material with dimensions of 1 200 mm in two or three dimension can realistically only be reduced to about 300 mm in size in the primary phase,” he says.

Similarly, in the secondary sizing stage, the ratio should be 3:1, which can reduce this 300 mm coal down to 100 mm. In the tertiary sizing stage, a ratio of 2:1 is the norm, breaking the material down further to the minus 50 mm size that the end-user usually requires.

“Trying to operate outside the boundaries of these reduction ratios invariably leads to increased wear and running costs,” he says. “Putting over-sized material – say, larger than 150 mm material – into a tertiary sizer designed for 100 mm material, prevents the positive ‘bite’ that breaks the product down. Instead, the size and geometry of the pieces means that they do not pass cleanly through the rotors, and cause undue wear on the rotor teeth and other components.”

He emphasises that trying to reduce capital expenditure by having fewer sizing stages – and therefore less equipment – is usually false economy. With the capital cost of this equipment making up only 8% to 10% of its total cost of ownership over its lifespan, the operating cost normally outweighs any upfront saving by orders of magnitude.

FLSMIDTH GOES LOCAL IN GHANA WITH NEW OFFICE OPENING

FLSmidth is further entrenching its Africa footprint with the opening of a new subsidiary company in Accra, the capital of Ghana.

According to Deon de Kock, FLSmidth country head in South Africa and vice president in Sub-Saharan Africa, the move has been made in response to the company’s critical mass of product in the region, and the strategic goal of being closer to customers.

“We have done business for many decades in West Africa and have a wide network of distributors and agents,” De Kock says. “This exciting development is our next step in enhancing our capacity as productivity partners with this customer base; as a worldwide group we can leverage our global resources and assets, and with the Ghana office can also be more responsive at a local level.”

The new presence in Accra will provide a hub for regional operations as there is already a large installed base not just in Ghana but in other neighbouring countries including Ivory Coast, Burkina Faso and Mali and possibly also Guinea.

“We are positioning for growth, not only for FLSmidth but for our customers in that area,” De Kock says. “Being closer to users and their sites also means that we can gain more detailed insights into their applications and challenges. This, in turn, sharpens how we conduct our service and support activities, and helps us fine tune the ways that we add value to customers’ operations and contribute to their growth.”

Deon de Kock, FLSmidth country head in South Africa and vice president in Sub-Saharan Africa.

“The office capacity will therefore comprise our own people who will be trained, focused and mentored to expertly represent FLSmidth to our existing and potential customer base,” says De Kock. “This is requiring substantial investment in people, infrastructure and systems, but is a crucial part of re-aligning our direct and indirect service channels to better serve our customers. We appreciate the contribution made by our distributor network up to this point, but we must now take the next step in terms of the natural progression of our growth trajectory.”

With well-known local expert Joseph Appiah Kubi appointed as the general manager, the Accra office will be staffed by Ghanaian nationals. This is in line with the view of FLSmidth that local skills, experience and expertise are vital to ensure a good understanding of customers and local conditions, and to provide optimal service levels. The office is expected to be fully operational by September 2017.

Joseph Appiah Kubi, general manager, FLSmidth Accra Office Ghana.

The facility will also be a valuable venue for product and process training for staff and customers, and will provide a well-positioned stop-off point for customers passing through Accra.

“It is clear that there are positive signs of recovery in the minerals sector in West Africa, especially in the gold mining segment,” he says. “We look forward to building up our own brand and in-house resources in this region, and working more closely than ever with customers there.”